Orthopaedic prostheses are commonly utilized to repair or replace damaged bone and tissue in the human body. For example, a knee prosthesis can include a tibial baseplate that is affixed to a resected or natural proximal tibia, a femoral component attached to a resected or natural distal femur, and a tibial bearing component coupled with the tibial baseplate and disposed between the tibial baseplate and femoral component. Knee prostheses frequently seek to provide articulation similar to a natural, anatomical articulation of a knee joint, including providing a wide range of flexion.
The tibial bearing component, also referred to as a tibial insert or meniscal component, can be used to provide an appropriate level of friction or contact area at the interface between the femoral component and the tibial baseplate. For a knee prosthesis to provide a sufficient range of flexion with a desirable kinematic motion profile, the tibial bearing component or tibial baseplate can be sized or oriented to interact appropriately with the femoral component of the knee prosthesis throughout the flexion range.
A given prosthetic component design, such as a tibial baseplate, tibial bearing component, or femoral component, can be provided to a surgeon as a kit including a variety of different sizes or prosthesis styles. During the surgical implantation procedure, such a kit can allow the surgeon to choose an appropriate component size or style on the basis of pre-surgery planning or intraoperative assessment of fit, such as how closely the component matches the natural contours of a patient's bone. Further, such a kit can allow the surgeon to choose an appropriate component size or style on the basis of kinematics, such as how smoothly the assembled knee joint prosthesis functions in conjunction with adjacent soft tissues and other anatomical structures. Soft tissue considerations can include proper ligament tension and minimization of soft tissue impingement upon prosthetic surfaces, for example.
In addition to prosthetic sizing, the orientation of a prosthetic component on a resected or natural surface of a bone can impact surgical outcomes. For example, the rotational orientation of a tibial baseplate and tibial bearing component with respect to a resected proximal tibia can affect the interaction between the corresponding femoral prosthesis and the tibial bearing component. The nature and amount of the coverage of a tibial baseplate over specific areas of the resected proximal tibia can also affect the fixation of the implant to the bone.